Grant Award and Removal Exploration for the D.F. Riley Grist Mill Dam in MA
Connecticut River Conservancy is working with the private dam owners, The Nature Conservancy, and other partners to explore removal.
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Dam Removal
River restoration includes improving fish passage and flood resiliency at “pinch points” in our rivers. These obstacles include obsolete dams no longer serving a useful purpose, and undersized culverts that block or hinder fish and other aquatic animals from accessing their entire watershed. CRC works with many partners to safely remove dams and upgrade culverts. Our accomplishments since 2014:
There are over 3,000 dams in the Connecticut River watershed. Most of them are obsolete. In addition, there are 44,000 stream crossings (bridges and culverts), many of which are undersized.
Why Remove Dams?
Fish Passage
Removing the old dams, building fish ladders at active hydro dams, and replacing culverts with larger flood and fish-friendly structures allows fish to move upstream to spawn and find colder water during the warm summer months.
Creating fish and aquatic animal passage helps reestablish natural cycles in rivers, allowing migratory fish, mussels, amphibians, turtles and a host of aquatic invertebrates access to critical habitat to reproduce. Learn more about migratory fish in the Connecticut River.
Flood Resilience
By removing obsolete dams and undersized culverts we create natural stream flows that improve flood resiliency in our communities.
Each dam removal lowers the flood elevation level and provides additional storage capacity within the river channel during the next big storm. Non-flood control dams do not provide flood storage capacity during large storm events; these obsolete dams only act as a small speed bump during the high flow events.
Dam Safety
Poorly maintained dams or those that have outlived their useful life are at risk of failing. Dam failure can cause flooding and damage to upstream and downstream infrastructure, homes, businesses, and ecosystems. Any polluted sediment trapped behind a dam is also released.
With severe storms becoming more common, dam failure is a growing threat to communities. The National Inventory of Dams is a helpful resource to look at the number of dams in your state, along with their hazard potential.
Water Quality
Dam removal improves water quality by increasing water flow and oxygen levels and reducing water temperatures critical for aquatic organism health.
Many projects also remove the accumulated sediment behind the dam which may contain excess nutrients such as nitrogen and phosphorus that can be harmful to a healthy river system.
How We Remove Dams
CRC works with private landowners, towns, and other owners of these structures to facilitate dam removal so that our rivers are healthier for everyone to enjoy.
Agreement
Communicate with landowners to ensure there is agreement on moving forward with a potential project.
Permits
Secure all necessary local, state, and federal permits legally required for dam removal.
Assessment
Collect information on site structure, environment, potential benefits, and feasibility of moving forward.
Funding for Removal
Another round of funding must be secured for the implementation of construction work.
Funding for Design
Secure funding to move ahead with the design phase - which usually involves grants and regional partnerships.
Construction
Implement site access, water and sediment management, dam removal, channel and flood bench construction.
Project Design
Engineers conduct field investigations, surveys, and modeling to create a design plan & cost estimate.
Restoration
Plant native trees, shrubs and grasses along the riverbank to ensure long-term stability and ecological health.
This process can take 3-7 years! After project management and completion, we also monitor the site for several years to document the long-term impact and share results with regional partners and the public.
CRC is currently pursuing multiple dam removal projects throughout the watershed, as well as several culvert replacement projects. Grant applications and funding proposals are being submitted to federal and state agencies and many Foundations. This multi-year campaign is focused on tributaries to the Connecticut River watershed where native fish and other organisms are prevented from moving upstream to spawn.
Dam Removal News
For questions about dam removal with Connecticut River Conservancy, contact Ron at rrhodes - at - ctriver.org.
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